Cohesion: Attraction Between Like Molecules

Dripping SyrupCohesion is the attractive force between like molecules, such as between two water molecules or between two syrup molecules.

The syrup in the photo forms a single cascading stream because the syrup molecules are attracted to each other.

Discover Cohesion Yourself

Wet your thumb and forefinger with water. Press these two fingers together, and then slowly separate them. Notice the string of water between your fingers. How far apart can you move your fingers before this thread of water breaks.

Repeat this investigation replacing the water with syrup.

Which material, water or syrup, forms a longer thread between your fingers?(syrup)

Which material is more cohesive? (syrup)

Which material is more viscous (thicker, doesn’t flow easily)? ( syrup)

FYI: Viscosity is a measure of how easily a substance flows.

33101X: Sticky, Gloppy, Wacky, and Wonderful Experiments Sticky, Gloppy, Wacky, and Wonderful Experiments